He had thousands of students, many of ______ gained great success in their own field.

He asked a lot of questions, none of ______ was easy to answer.

He asked a lot of questions, and none of ______ was easy to answer.

He told me that he had two girl-friends, neither of _______ knew anything about the other.

He told me that he had two girl-friends, and neither of _______ knew anything about the other.

They put forward a lot of plans at the meeting, none of _______ carried out in their work.

They put forward a lot of plans at the meeting, none of _______ were carried out in their work.

They put forward a lot of plans at the meeting, but none of _______ were carried out in their work.

If you want a double room, _____ will cost another ￡15.

Whether you go or not, _______ is quite all right with me.